ASCO Issues New Recommendation for ESR1 Testing
- The American Society of Clinical Oncology (ASCO) has issued a new recommendation that some women with advanced breast cancer be tested for a mutation in the ESR1 gene.
- The recommendation comes after the approval of a drug called elacestrant (Orserdu) earlier this year. The drug showed promise in treating people whose tumors were ER-positive, HER2-negative, had the ESR1 mutation, and had continued to grow after hormone therapy.
- Elacestrant is a type of drug known as a selective estrogen receptor degrader (SERD). It is taken orally in pill form.
- The updated recommendation was based on a trial that demonstrated elacestrant’s success in treating this specific population of breast cancer patients.
The recommendation comes after the Food and Drug Administration (FDA) approved a drug called elacestrant (Orserdu) for certain women with stage 3 and 4 breast cancer earlier this year.
Read MoreThe EMERALD study & elacestrant’s success
The approval comes after research that suggests ESR1 gene mutations cause resistance to hormone therapy, which is often used when treating breast cancer, according to Memorial Sloan Kettering Cancer Center.The EMERALD study demonstrated that these patients exhibited a significant enhancement in progression-free survival when treated with elacestrant, as opposed to the standard-of-care endocrine therapy.
Elacestrant is a type of drug known as a selective estrogen receptor degrader (SERD). The drug is taken orally in pill form.
“The new approval for elacestrant is very exciting, because it’s actually the first class that is an oral medication that is attacking directly the estrogen receptor of cancer cells,” Dr. Sylvia Adams, Director of the Breast Cancer Center at NYU's Perlmutter Cancer Center, told SurvivorNet at the time of its approval.
“We do have similar drugs that are injectables, but they are obviously very painful because they have to be injected intramuscularly into the buttocks, so having an oral medication is preferred.”
Dr. Sylvia Adams explains why elacestrant’s approval is so promising.
What are the current treatment options?
Patients lacking ESR1 mutations did not observe any improvement with elacestrant.
Consequently, the guideline advises the routine testing of ESR1 mutations in HR-positive, HER2-negative metastatic breast cancer patients who experience recurrence or progression on endocrine therapy, regardless of whether they are undergoing a type of targeted therapy known as CDK4/6 inhibitor therapy or not.
For patients with ESR1 mutations, treatment options include elacestrant or other types of endocrine therapy either alone or in combination with targeted agents such as everolimus or alpelisib for tumors with PIK3CA mutations.
On the contrary, patients with ESR1 wild-type tumors possess diverse endocrine therapy alternatives, including fulvestrant, an aromatase inhibitor, or tamoxifen monotherapy.
Moreover, these patients can also consider combining endocrine therapy with targeted agents like everolimus or alpelisib for tumors with PIK3CA mutations.
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